Omg it's ridiculous how I'm ALWAYS tired I fall asleep in almost every class I take , fall asleep on the bus (coming to & from school) and I fall asleep when I get home from school. I have a heart palpitation and take medicine for it but there is no way that makes me that tired...

I can have 4 hours of sleep, be falling asleep at work, then go to bed early... Only to be wide awake for hours.
I can get 8 hours of sleep, be drowsy all day, then wide awake when I get to bed.
What is wrong with me?